Round undulating blade, blade module, and rotary assembly for shredder

Abstract

The present invention relates to a round undulating blade for shredder, where a sheet metal is integrally formed into a round undulating blade to serve as the blades for constructing a blade module. The blade includes: a periphery; an undulating blade flank including at least two cambers having a first curvature and at least two cambers having a second curvature alternatively arranged with respect to the cambers having the first curvature; and hooked edges formed on the periphery of the cambers having the first curvature, wherein the undulating blade flank of the blade serves to cut paper along a longitudinal direction to form paper strips having double-tapering end, and the hooked edges serve to cut the strips along a horizontal direction into paper chips. These characteristics help to reduce the manufacturing cost, reduce the motor load and power consumption, to thereby enhance the market competitiveness.

1. A blade set for a shredder comprising two adjacent round undulating blades, each blade comprising a blade flank with at least two cambers having a first curvature and at least two cambers having a second curvature alternatively arranged with respect to the cambers having the first curvature. 
     
     
       2. A blade set according to  claim 1  wherein each blade has at least one rib. 
     
     
       3. A blade set according to  claims 1  or  2  wherein each blade has at least one hooked edge formed on the periphery of the blade. 
     
     
       4. A method of shredding paper into pieces with a wide center which tapers at each end comprising the steps of providing multiple blade sets comprised of adjacent round undulating blades with hooked edges, the blade sets disposed on opposing interlaced rotating shafts and feeding paper between the two rotary shafts thereby shredding the paper into pieces with a wide center which tapers at each end.